Battery-tester.



E. i.. CLARK.

BATTERY TESTER. APPLICATION FILED MAR. 9. I9I5.

Patented. July 8, 1917.

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NVENTOR. EMERE N L. CLARK B y TTOR/VY I WITNESSES:

UN AT AEN EMERSON L. CLARK, OF LAKEWOOD, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

NATIONAL CARBON COMPANY, INC., A CORPORATION OF NEW YORK. u

BATTERY-TESTER.

Specification of Letters Patent.

Patented July 3, 1917.

Original application :tiled April 26, 1913, Serial No. 763,715. Divided and this application filed. March 9,

To all whom t may concern.'

Be it known that I, Eunnsou L. CLARK, a citizen of the United States, residing at Lakewood, in the county of 'Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Battery-Testers, of which the following is a full, clear, and exact description.

This invention relates to a device for testing batteries, and is adapted jj articularly to be used in connection with dry cells.

One object of this invention is to construct a reliable battery tester of new design at low cost.

Another object is to secure an instrument which will indicate if a battery is up to a certain definite standard by means of an audible signal or by the sense of touch.

A further object is to provide an instrument that is adjustable and which will not operate below a deiinite value.

Other objects will appear in the appended description in which:

Figure 1 is a cross section of the battery tester. l

Fig. 2 is a cross section of a slightly different form of battery tester.

Fig. 3 is a partial view showing a suitable scale for indicating the adjustment.

Fig. i is another type of scale for use on the battery testers shown.

Fig. 5 is a somewhat diEerent scale for use similar to those of Figs. 3 and 4L.

Referring to Fig. 1, the tester consists of a cylindrical inclosing tube 1 formed preferably of some non-magnetic conducting metal such as brass, and of small diameter, say about 5g to 11s, so that the instrument can be conveniently carried in the pocket. Vithin the tube the elements of the tester are placed as hereinafter described. A hollow contact or terminal 2 made of non-magnetic conducting material has a chamber or recess 3 therein and a soft iron plunger or armature 4 is placed in the chamber. A pin 9.1 is attached to the plunger 4f and passes through a central hole 22 longitudinally eX- tending through a core member S, so that when the plunger is raised, the pin 21 extends through the member and strikes the finger placed over the opening. The end of the pin 9.1 can also be seen when the plunger is raised and hence it can indicate that the plunger has been raised. The adjustment Serial No. 13,149.

between the core S and Contact 2 can be secured by adding non-magnetic washers Q1. The instrument shown in Fig. '2 is of the same type as that of Fig. 1, the difference being in the manner of operating the pin. The lower end of the pin 21, which is preferably of non-magnetic material, is attached to the head 23 moving loosely in a recess 2a of a larger diameter than the lower recess 3 in which the armature L operates. The opening 2li is closed by the threaded end of the member 8 as in the preceding figure.

Figs. 3, 4t and 5 illustrate three typical scales for indicating the current required to operate the instrument. In the form shown in Fig. 3, the indicator is a circular line or groove cut around the contact member 2. This guide line is visible through a slot 26 cut in the cylinder 1, and a longitudinal scale 27 is marked on the cylinder at the edge of the slot. The scale may be calibrated to indicate the point at which the magnet picks up for the various currents. In Fig. 4 the scale 9.7 is marked on the Contact member 2 and the base line 28 of the tube serves as the zero line. In Fig. 5, the scale 29 ismarked around the lower edge of the inclosing cylinder, and an arrow 30 .serves as the Zero line. This form of scale is adapted for instruments in which the vertical distance, through which the con-,

tact 2 is moved for a given variation of current, is small. Any of these forms can be used on the battery testers of Figs. 1 and 2, and other forms will also be suitable, those shown being merely illustrative.

The operation of the instruments of Figs. 1 and 2 is essentially the same, as is also the manner of adjustment. In Fig. 1, when the terminals 2 and 13 are applied to the terminals of a battery, the coil 9 will magnetize the core 8 which attracts the plunger 4 and raises the pin or indicating means so that its end extends out of the member 8. The operator, by placing his finger over the upper end of the tester, will feel the imw pact of the pin and know that the armature has picked up. If the armature sticks to the core on account of residual magnet ism, it can be pushed away by manipulating the pin.

The instruments can be set to operate above a certain value, say 6 amperes, and then used to tell whether a cell should be discarded or not. If the armature picks up it Will be known that the cell is all right. If it does not pick up the cell can be discarded as depleted.` The instruments, however, are preferably made with adjustable scales as in Figs. 3, 4f and 5, so that the operator, in testing a battery, would adjust the contact piece from high readings to lower ones until-the click or impact indi-y cates that the armature has been picked up.

The value of the current can then be read on the scale. lThis value is the-current that the battery can produce on shortcircuit, for the Winding on thecoil can be made to have negligible resistance. The testerfcan also be Wound to take a small currcntand by proper calibration it Will indicate the voltage.'-

Inr all of the battery'testers shown, the

shape of the armature and inclosing tube is,v

vsecured-to said metallic member and electrically `connected .to the coil, an armature or plunger in the head, an indicating device extending through said member adapted to be moved when the armature or plunger is attracted by the coil, and a flexible terminal electrically connected with the other end of the coil.

2. A battery tester consisting'of a hollow core of magnetic material, a coil of Wire Wound thereon, a contact piece secured to the end of said core and electrically connected with one end of the coil, an armature or plunger adaptedV to be movedsbyfthe field.,

produced by a current traversing the coil, and an indicating device extending through said core adapted tobe movediby said arma. ture or plunger. n

3. A battery tester consistingof a hollow iron core,-a coil of Wire Wound thereong'a hea d of -nonimagnetic material secured` .to

said core, a non-magnetic 4rod.` extending...

loosely throughsaid coreand intosaid head, l

an armature in the head spacedgfrom the end or said rod, said armatureadaptedto movesaid rod When moved throughithe in luence of the'magnetie fieldl of 'said coil..

l. A battery testervconsisting cfa' hollenrv iron core7 a coil of Wirewvoundfthereon, .a f

head of non-magnetic material secured. to the end yof said core-,a non-magnetic rod .extending through said core and into the head, a disk secured-to said rod andan armature in said head spaced `from said disk.V

In testimony .WhereoLI hereunto aiiixfmy Signature in the presence of'witnesses.

EMERSON L. CLARK.' llitnesses:

S. H. FLEMING, H. Grnovin..n

Copies of this patent may be obtained for five cents eachgbyadd-ressing the .5 Commissioner Vof ,-IEatent'swf` Washigton,1). 0. 

